Waste-to-resource solution helps the Suzhou Industrial Park become a model of synergetic recycling

The Suzhou Industrial Park (SIP) is among the fastest-growing and most internationally-competitive development zones in eastern China, as well as an important hallmark of China’s ultra-resilient economy. To drive the development of the circular economy at SIP, SUEZ began to provide sludge disposal and waste-to-resource treatment services to the park in 2011 and expanded its services to include hazardous waste treatment in 2017. SUEZ now converts waste to resources and energy for SIP to promote successful resource recycling.
The mission

Since its inception, SIP has sought to “prevent pollution on all fronts, maximize resource and energy utilization, and minimize pollutant discharge”. To support the development of the circular economy in line with SIP’s central planning of the “five 100%”, SUEZ designed, invested in, built, and operates the first sludge drying and disposal project in Jiangsu Province in the park.


The development of SIP has attracted a growing number of industrial customers, each having its own characteristics, and together generating a diverse range of hazardous waste. Such waste is prone to reactions and poses a great threat to the environment. SUEZ replicated its proven hazardous waste treatment experience and recycling model from the Shanghai Chemical Industry Park in SIP so that hazardous waste can be disposed of more safely and with higher standards.

Our solution

Turning sludge into resources and unlocking industrial synergies

SUEZ’s sludge treatment project in SIP uses SUEZ’s EvaporisTM 2E two-stage sludge drying process, which reduces energy consumption while safely disposing sludge and effectively reduces the sludge moisture content from 80% to 10%. Thanks to its high energy content, the dried sludge can be used as an alternative fuel, replacing coal.

Additionally, our sludge project adopts a circular and zero-discharge model that converts sludge into resources and mitigates climate change, achieving close interactions and strong synergies among the sludge drying plant, co-generation power plant, and wastewater treatment plant.


The sludge plant can treat 600 tons of wet sludge generated from the park’s wastewater treatment plant every day and has operated 24/7, year-round since it was commissioned 11 years ago, achieving daily clearance of the generated sludge. The project’s operational stability and energy efficiency are industry-leading, consuming only 0.63 ton of heat recovery steam per ton of wet sludge treated, 40% lower than other similar processes.

Disposing of hazardous waste to recover energy

Our hazardous waste treatment facility has an annual capacity of 30,000 tons and can treat 23 major categories and 286 sub-categories of hazardous waste, serving over 700 hazardous waste generators.

We have established a unique “ID card” for each type of hazardous waste to fully capture the characteristics of hazardous waste and ensure safe and reliable treatment. So far, we have established effective IDs for 4,000 types of waste.

In the process of hazardous waste treatment, the high-temperature flue gas generated from hazardous waste incineration is passed through the heat recovery boiler to produce steam for use by adjacent enterprises, offering a significant decarbonization benefit. Additionally, as the only hazardous waste treatment project in Jiangsu Province that adopts the EU 2010 emission standards, our facility goes beyond domestic flue gas and odor treatment standards, meeting the most stringent European standards with zero nitrogen and phosphorus emissions.

The results
  • Our sludge drying project has been recognized as a model of the circular economy for reducing CO2 emissions by 20,000 tons per year through resource recycling, and it has been awarded the Climate Change Solutions Innovation Award by the France China Committee as a, “replicable case study of third-party environmental treatment in China”, and a “Jiangsu Province Circular Economy Demonstration Project”.
  • Our hazardous waste treatment project recovers 70,000 tons of steam per year, reduces greenhouse gas emissions by approximately 13,000 tons of CO2 equivalent, and saves 4.76 million m3 of natural gas. For its excellent performance in the circular economy, energy savings, and emissions reduction, the project was awarded the Suzhou Industrial Park’s 2021 Excellent Case Study Award for Green and Low Carbon Solutions.
  • SUEZ’s reduction of sludge and hazardous waste, harmless disposal, and waste-to-resource conversion turn sludge into valuable resources and neutralize the environmental threat from hazardous waste. This not only promotes the circular economy, but also protects the ecological environment and raises the environmental safety of the park.

sludge treatment capacity


CO2 emissions reduction through sludge-to-resource conversion

24/7 uninterrupted operation of sludge disposal facility

hazardous waste treatment capacity


zero emissions of nitrogen and phosphorus
hazardous waste treatment facility enforces the most-stringent European standards
steam recovered through the hazardous waste treatment project